Add optional offline mirror pruning (#2836)

Author: dguo

__tests__/commands/remove.js

@@ -140,3 +140,13 @@ test.concurrent('removes subdependencies', (): Promise<void> => {
     assert.equal(lockFileLines[0], 'dep-c@^1.0.0:');
   });
 });
+
+test.concurrent('can prune the offline mirror', (): Promise<void> => {
+  return runRemove(['dep-a'], {}, 'prune-offline-mirror', async (config, reporter) => {
+    const mirrorPath = 'mirror-for-offline';
+    assert(!await fs.exists(path.join(config.cwd, `${mirrorPath}/dep-a-1.0.0.tgz`)));
+    // dep-a depends on dep-b, so dep-b should also be pruned
+    assert(!await fs.exists(path.join(config.cwd, `${mirrorPath}/dep-b-1.0.0.tgz`)));
+    assert(await fs.exists(path.join(config.cwd, `${mirrorPath}/dep-c-1.0.0.tgz`)));
+  });
+});

__tests__/commands/upgrade.js

@@ -165,3 +165,16 @@ test.concurrent('doesn\'t warn when peer dependency is still met after upgrade',
     'peer-dependency-no-warn',
   );
 });
+
+test.concurrent('can prune the offline mirror', (): Promise<void> => {
+  return runUpgrade(['dep-a@1.1.0'], {}, 'prune-offline-mirror', async (config): ?Promise<void> => {
+    const lockfile = explodeLockfile(await fs.readFile(path.join(config.cwd, 'yarn.lock')));
+    assert(lockfile.indexOf('dep-a@1.1.0:') === 0);
+
+    const mirrorPath = 'mirror-for-offline';
+    assert(await fs.exists(path.join(config.cwd, `${mirrorPath}/dep-a-1.1.0.tgz`)));
+    assert(!await fs.exists(path.join(config.cwd, `${mirrorPath}/dep-a-1.0.0.tgz`)));
+    // In 1.1.0, dep-a doesn't depend on dep-b anymore, so dep-b should be pruned
+    assert(!await fs.exists(path.join(config.cwd, `${mirrorPath}/dep-b-1.0.0.tgz`)));
+  });
+});

__tests__/fixtures/remove/prune-offline-mirror/.yarnrc

@@ -0,0 +1,6 @@
+# THIS IS AN AUTOGENERATED FILE. DO NOT EDIT THIS FILE DIRECTLY.
+# yarn lockfile v1
+
+
+yarn-offline-mirror "./mirror-for-offline"
+yarn-offline-mirror-pruning true

__tests__/fixtures/remove/prune-offline-mirror/mirror-for-offline/dep-a-1.0.0.tgz

@@ -0,0 +1,6 @@
+{
+  "dependencies": {
+    "dep-a": "1.0.0",
+    "dep-c": "1.0.0"
+  }
+}

__tests__/fixtures/remove/prune-offline-mirror/mirror-for-offline/dep-b-1.0.0.tgz

@@ -0,0 +1,17 @@
+# THIS IS AN AUTOGENERATED FILE. DO NOT EDIT THIS FILE DIRECTLY.
+# yarn lockfile v1
+
+
+dep-a@1.0.0:
+  version "1.0.0"
+  resolved dep-a-1.0.0.tgz#d170a960654001b74bdee4747e71f744ecf0a24f
+  dependencies:
+    dep-b "1.0.0"
+
+dep-b@1.0.0:
+  version "1.0.0"
+  resolved dep-b-1.0.0.tgz#fa3fab4e36d8eb93ac74790748a30547e9cb0f3f
+
+dep-c@1.0.0:
+  version "1.0.0"
+  resolved dep-c-1.0.0.tgz#67156f3be73744a1d4b7c959c4d0d3575e54f442

__tests__/fixtures/remove/prune-offline-mirror/mirror-for-offline/dep-c-1.0.0.tgz

@@ -0,0 +1,6 @@
+# THIS IS AN AUTOGENERATED FILE. DO NOT EDIT THIS FILE DIRECTLY.
+# yarn lockfile v1
+
+
+yarn-offline-mirror "./mirror-for-offline"
+yarn-offline-mirror-pruning true